MySQL Cluster Members Test

This test monitors the current status of each node in the target MySQL cluster and also reports whether/not the node is a primary node. In addition, this test also reports whether/not any switchover occurred, and whether/not the node is read-write node. Using this test, administrators can proactively figure out error-prone nodes, nodes that are unreachable and nodes that are removed/missing and take corrective actions for those nodes to be available.

Target of the test : A MySQL Cluster

Agent deploying the test : An external agent

Outputs of the test : One set of results for each node on the target MySQL Cluster database server being monitored.

Configurable parameters for the test
Parameter Description

Test Period

How often should the test be executed

Host

Specify Host name of the server for which the test is to be configured in this text box.

Port

Specify the port to which the specified host listens in this text box.

Database(DB)

Specify the name of a database on the target MySQL Cluster database server being monitored in the Database text box.

Username and Password

The eG agent has to be configured with the credentials of a user who has server-wide Process and Select privileges on the monitored MySQL Cluster database server in the Username and Password text boxes. To know how to create such a user, refer to Pre-requisites for Monitoring the MySQL Cluster

Confirm Password

Confirm the Password by retyping it in the Confirm Password text box.

Allow Public Key

By default, the Allow Public Key flag is set to No. But, if the specified USER is created with caching_sha2_password as the authentication plugin, then the eG agent can connect to the target database cluster using RSA public key. To this effect, you have to set Allow Public Key flag to Yes.

SSL

By default, the SSL flag is set to No, indicating that the target MySQL Cluster server is not SSL-enabled by default. To enable the test to connect to an SSL-enabled MySQL Cluster server, set the SSL flag to Yes.

Verify CA

If the eG agent is required to establish an encrypted connection with the target MySQL Cluster server by authenticating the server's identity through verifying the server CA certificate, set Verify CA flag to Yes. By default, this flag is set to No.

Truststore Password

This parameter is applicable only if the Verify CA parameter is set to Yes. To verify the target server certificate, provide the password of the truststore file which contains the server CA certificate in the Truststore Password text box. By default, this parameter is set to none.

Confirm Password

Confirm the Password by retyping it in the Confirm Password text box.

Keystore Password

This parameter is applicable only if the Verify CA parameter is set to Yes. To establish a connection with the target MySQL Cluster server, the eG agent needs to have access to the client certificate. For this provide the password of the keystore file which contains the client certificate in the Keystore Password text box. By default, this parameter is set to none.

Confirm Password

Confirm the Password by retyping it in the Confirm Password text box.

Include Available Nodes

In the Include Available Nodes text box, provide a comma-separated list of all the available nodes to be included for monitoring. This way, the test monitor and collect metrics from all the available nodes in the cluster. By default, this parameter is set to none. The format of this configuration is: HOSTNAME:PORT, for example, 172.16.8.136:3306,172.16.8.139:3306

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD frequency.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

  • The eG manager license should allow the detailed diagnosis capability
  • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
Measurements made by the test

Measurement

Description

Measurement Unit

Interpretation

Status

Indicates the current status of this node.

 

The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
MISSING OR REMOVED 0
UNREACHABLE 1
ERROR 2
OFFLINE 3
RECOVERING 4
ONLINE 5

Note:

This measure reports the Measure Values listed in the table above to indicate the current state of each node. However, in the graph, this measure is indicated using the Numeric Values listed in the table above.

Is this primary node?

Indicates whether/not this node is a primary node.

 

This measure is not reported for the Summary descriptor.

The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
No 0
Yes 1

Note:

This measure reports the Measure Values listed in the table above to indicate whether/not the node is a primary node. However, in the graph, this measure is indicated using the Numeric Values listed in the table above.

Has the role of this node changed?

Indicates whether/not the role of this node has switched, i.e., whether a primary node has switched over to secondary node and vice versa.

 

The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
No 0
Yes 1

Note:

This measure reports the Measure Values listed in the table above to indicate to indicate whether/not role of the node has switched. However, in the graph, this measure is indicated using the Numeric Values listed in the table above.

Is this node in read-write mode?

Indicates whether/not this node is in read-write mode.

 

This measure is not reported for the Summary descriptor.

The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
No 0
Yes 1

Note:

This measure reports the Measure Values listed in the table above to indicate to indicate to indicate whether/not the node is in read-write mode. However, in the graph, this measure is indicated using the Numeric Values listed in the table above.

Number of read-write nodes

Indicates the number of read-write nodes in the cluster.

Number

This measure is reported only for the Summary descriptor.

If the value of this measure is less than 1 then it is a cause for concern.

Number of read-only nodes

Indicates the number of read only nodes in the cluster.

Number

This measure is reported only for the Summary descriptor.

Read-only nodes are replicas of a cluster’s primary node located in additional geographical regions. Using read-only nodes reduces latency for users connecting from those regions.

Number of online nodes

Indicates the number of nodes in the cluster that are currently online.

Number

This measure is reported only for the Summary descriptor.

Number of recovering nodes

Indicates the number of nodes in the cluster that are currently in recovering state.

Number

This measure is reported only for the Summary descriptor.

Number of offline nodes

Indicates the number of nodes in the cluster that are currently offline.

Number

This measure is reported only for the Summary descriptor.

A low value is desired for this measure.

Number of error nodes

Indicates the number of nodes in the cluster that are currently in error state.

Number

This measure is reported only for the Summary descriptor.

A low value is desired for this measure.

Number of unreachable nodes

Indicates the number of nodes in the cluster that are currently unreachable.

Number

This measure is reported only for the Summary descriptor.

A low value is desired for this measure.

Primary count

Indicates the number of primary nodes in the cluster.

Number

This measure is reported only for the Summary descriptor.

Use the detailed diagnosis of this measure to find the Host ID, Host name, Port, and Access mode of the primary nodes.

Secondary count

Indicates the number of secondary nodes in the cluster.

Number

This measure is reported only for the Summary descriptor.

Use the detailed diagnosis of this measure to find the Host ID, Host name, Port, and Access mode of the secondary nodes.

Health state

Indicates the current health state of this cluster.

 

This measure is reported only for the Summary descriptor.

The values reported by this measure and their numeric equivalents are available in the table below:

Measure Value Numeric Value
Good 2
Degraded 1
Critical 0

Note:

By default, this measure reports current health of the cluster. The graph of this measure however, is represented using the numeric equivalents only - 0 to 2.

Total number of nodes

Indicates the total number of nodes in the cluster.

Number

This measure is reported only for the Summary descriptor.